1. Field of the Invention
The present invention relates to the field of scissors, shears, knives and similar cutting implements and more particularly to a novel such cutting implement construction having a permanent or replaceable cutting blade which is separate from the implement shank or handle residing in a recess or cavity between a welded cover and the shank or handle.
2. Brief Description of the Prior Art
In the past, major inconveniences with which a surgeon, barber or other worker had to contend involve the problem of maintaining a sharp, keen cutting edge on the instrument in order to perform the best work. The user has to continually maintain these sharp instruments in order to obtain proper performance. This problem is also presented to a surgeon who, in addition, is faced with the problem of sanitation of his surgical instrument. Therefore, attempts have been made to utilize cutting blades adapted to be mounted on the shanks of scissors or the like for easy and quick removal without damage to the latter or for long lasting or permanent installation. However, problems have been encountered which stem largely from the fact that insertion of such blades, whether of metal or ceramic construction, into the respective shanks of a scissors or handle of a knife is not guided and relies solely on feel and visual observation. Also, removal of blades, when dull or damaged, is difficult and generally requires the two hands of the user to successfully eject or remove blades.
In other instances, problems have been encountered with premature release or lack of retention for the blades on the shank so that blades sometimes dislodged and fell from the shank when in use.
Manufacturing of cutting blades of metal or ceramic materials is difficult and particularly the fabrication of the implement to accept the mounting or joining of the blade with the scissor shank or the knife handle. When such prior instruments are used in specialized situations, such as when surgical instruments are employed, extremely hard and dense materials are used for producing the scissors or implement. Such compositions are difficult, and therefore expensive to drill, form or otherwise provide the necessary recesses, openings, apertures or the like in order to fabricate a high performance instrument. The cost involves not only highly skilled labor, but the cost of cutting implements which are required to form the surgical steel used in the fabrication of such instruments.
Therefore, a long standing need has existed to provide a cutting implement for accepting replaceable or permanent blades, but which is self-indexing or registering so that the blade of either type may be automatically installed at its location on the implement. Additionally, it is preferred to have a positive retention means for holding the blade in position on a shank or handle so that it will not be inadvertently dislodged.